String str = '''
{"name": "${r0.name}", "age": 15}
'''

Map resultData = [:]
resultData.prepareRequestData0 = [name: 'kerry']

Map values = [:]
resultData.each{k, v ->
	values[k.replace('prepareRequestData', 'r')] = v
}

println SpecScriptEval.eval('"""' + str + '"""', values)